Experimental Evaluation of Available Computational Methods for Eddy Current and Hysteresis Losses for Cables Installed in Steel Pipes

2018 ◽  
Vol 33 (4) ◽  
pp. 1777-1786 ◽  
Author(s):  
Haowei Lu ◽  
Abdullah Bokhari ◽  
Tianqi Hong ◽  
Francisco de Leon
Keyword(s):  
Computational Methods ◽  
Eddy Current ◽  
Experimental Evaluation ◽  
Hysteresis Losses ◽  
Steel Pipes

Determination of eddy current losses and hysteresis losses in magnetic circuits of electrical machines

2020 ◽  
pp. 54-58
Author(s):  
S. M. Plotnikov
Keyword(s):  
Eddy Current ◽  
Magnetization Reversal ◽  
Eddy Currents ◽  
Technical Problem ◽  
Electrical Machines ◽  
Eddy Current Losses ◽  
Hysteresis Losses ◽  
Magnetic Circuits ◽  
Core Losses ◽  
Reversal Frequency

The division of the total core losses in the electrical steel of the magnetic circuit into two components – losses dueto hysteresis and eddy currents – is a serious technical problem, the solution of which will effectively design and construct electrical machines with magnetic circuits having low magnetic losses. In this regard, an important parameter is the exponent α, with which the frequency of magnetization reversal is included in the total losses in steel. Theoretically, this indicator can take values from 1 to 2. Most authors take α equal to 1.3, which corresponds to the special case when the eddy current losses are three times higher than the hysteresis losses. In fact, for modern electrical steels, the opposite is true. To refine the index α, an attempt was made to separate the total core losses on the basis that the hysteresis component is proportional to the first degree of the magnetization reversal frequency, and the eddy current component is proportional to the second degree. In the article, the calculation formulas of these components are obtained, containing the values of the total losses measured in idling experiments at two different frequencies, and the ratio of these frequencies. It is shown that the rational frequency ratio is within 1.2. Presented the graphs and expressions to determine the exponent α depending on the measured no-load losses and the frequency of magnetization reversal.

An Experimental Evaluation of Computational Methods For Determining Lattice Parameters Using Bragg-Brentano Powder Diffractometry

1993 ◽  
Vol 37 ◽  
pp. 87-93 ◽  
Author(s):  
E.A. Payzant ◽  
H.W. King
Keyword(s):  
Least Squares ◽  
Computational Methods ◽  
Experimental Evaluation ◽  
Lattice Parameters ◽  
Trial And Error ◽  
Internal Standards ◽  
Figures Of Merit ◽  
Standard Deviations

AbstractComputational methods for determining precision lattice parameters based on extrapolation, lattice refinement, least squares and trial and error indexing, with intermediate corrections for peak positions using external and internal standards, have been evaluated with respect to the ICDD published values for zincite. Lattice parameters can be routinely determined to an accuracy of one part in ten thousand without the use of external or internal standards, by using computational extrapolation on data with a well aligned and maintained diffractometer. Lattice refinement determination of lattice parameters was only effective, with respect to the ICDD values, when used in conjunction with external and internal Standards. Least squares yielded results with low standard deviations, but the use of standards did not reduce the refined sample displacement or zero angle errors, and gave an increased error in lattice parameters with respect to the ICDD values. The trial and error indexing, which can only be used with peak positions corrected with respect to both external and internal standards, gave relatively low de Wolff and Smith-Snyder figures of merit, but nevertheless yielded lattice parameters of the highest accuracy of one part in twelve thousand, with respect to the ICDD values.

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